org.springframework.xd.dirt.zookeeper

Class ZooKeeperConnection

java.lang.Object

org.springframework.xd.dirt.zookeeper.ZooKeeperConnection

All Implemented Interfaces:

org.springframework.context.Lifecycle, org.springframework.context.Phased, org.springframework.context.SmartLifecycle

public class ZooKeeperConnection
extends java.lang.Object
implements org.springframework.context.SmartLifecycle

A wrapper for a CuratorFramework instance whose lifecycle is managed as a Spring bean. Accepts ZooKeeperConnectionListeners to be notified when connection or disconnection events are received.

Author:

Mark Fisher, David Turanski, Patrick Peralta

Field Summary

Fields

Modifier and Type	Field and Description
static java.lang.String	DEFAULT_CLIENT_CONNECT_STRING The default client connect string.
static int	DEFAULT_CONNECTION_TIMEOUT The default ZooKeeper connection timeout in milliseconds.
static int	DEFAULT_INITIAL_RETRY_WAIT The default initial number of milliseconds between connection retries.
static int	DEFAULT_MAX_RETRY_ATTEMPTS The default number of connection attempts that will be made after a failed connection attempt.
static int	DEFAULT_SESSION_TIMEOUT The default ZooKeeper session timeout in milliseconds.

Constructor Summary

Constructors

Constructor and Description
ZooKeeperConnection() Establish a ZooKeeper connection with the default client connect string: "localhost:2181"
ZooKeeperConnection(java.lang.String clientConnectString) Establish a ZooKeeper connection with the provided client connect string.
ZooKeeperConnection(java.lang.String clientConnectString, java.lang.String namespace) Establish a ZooKeeper connection with the provided client connect string and namespace.
ZooKeeperConnection(java.lang.String clientConnectString, java.lang.String namespace, int sessionTimeout, int connectionTimeout, int initialRetryWait, int retryMaxAttempts) Establish a ZooKeeper connection with the provided client connect string, namespace, and timing values.

Method Summary

Methods

Modifier and Type	Method and Description
boolean	addListener(ZooKeeperConnectionListener listener) Add a ZooKeeperConnectionListener.
org.apache.curator.framework.CuratorFramework	getClient() Provides access to the underlying CuratorFramework instance.
int	getPhase()
org.apache.curator.RetryPolicy	getRetryPolicy() Return the Curator retry policy.
boolean	isAutoStartup()
boolean	isConnected() Checks whether the underlying connection is established.
boolean	isRunning() Check whether this client is running.
boolean	removeListener(ZooKeeperConnectionListener listener) Remove a ZooKeeperConnectionListener.
void	setAutoStartup(boolean autoStartup) Set the flag that indicates whether this connection should be started automatically.
void	setRetryPolicy(org.apache.curator.RetryPolicy retryPolicy) Set the Curator retry policy.
void	start() Starts the underlying CuratorFramework instance.
void	stop() Closes the underlying CuratorFramework instance.
void	stop(java.lang.Runnable callback) Closes the underlying CuratorFramework instance and then invokes the callback.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

DEFAULT_CLIENT_CONNECT_STRING

public static final java.lang.String DEFAULT_CLIENT_CONNECT_STRING

The default client connect string. Port 2181 on localhost.

See Also:

Constant Field Values

DEFAULT_SESSION_TIMEOUT

public static final int DEFAULT_SESSION_TIMEOUT

The default ZooKeeper session timeout in milliseconds.

See Also:

Constant Field Values

DEFAULT_CONNECTION_TIMEOUT

public static final int DEFAULT_CONNECTION_TIMEOUT

The default ZooKeeper connection timeout in milliseconds.

See Also:

Constant Field Values

DEFAULT_INITIAL_RETRY_WAIT

public static final int DEFAULT_INITIAL_RETRY_WAIT

The default initial number of milliseconds between connection retries.

See Also:

Constant Field Values

DEFAULT_MAX_RETRY_ATTEMPTS

public static final int DEFAULT_MAX_RETRY_ATTEMPTS

The default number of connection attempts that will be made after a failed connection attempt.

See Also:

Constant Field Values

Constructor Detail

ZooKeeperConnection

public ZooKeeperConnection()

Establish a ZooKeeper connection with the default client connect string: "localhost:2181"

ZooKeeperConnection

public ZooKeeperConnection(java.lang.String clientConnectString)

Establish a ZooKeeper connection with the provided client connect string.

Parameters:

clientConnectString - one or more host:port strings, comma-delimited if more than one

ZooKeeperConnection

public ZooKeeperConnection(java.lang.String clientConnectString,
                   java.lang.String namespace)

Establish a ZooKeeper connection with the provided client connect string and namespace.

Parameters:

clientConnectString - one or more host:port strings, comma-delimited if more than one

namespace - the root path namespace in ZooKeeper (or default namespace if null)

ZooKeeperConnection

public ZooKeeperConnection(java.lang.String clientConnectString,
                   java.lang.String namespace,
                   int sessionTimeout,
                   int connectionTimeout,
                   int initialRetryWait,
                   int retryMaxAttempts)

Establish a ZooKeeper connection with the provided client connect string, namespace, and timing values.

This class uses ExponentialBackoffRetry internally.

Parameters:

clientConnectString - one or more host:port strings, comma-delimited if more than one

namespace - the root path namespace in ZooKeeper (or default namespace if null)

sessionTimeout - ZooKeeper session timeout in milliseconds

connectionTimeout - ZooKeeper connection timeout in milliseconds

initialRetryWait - milliseconds between connection retries (base value)

retryMaxAttempts - number of connection attempts that will be made after a failed connection attempt

Method Detail

isConnected

public boolean isConnected()

Checks whether the underlying connection is established.

Returns:

true if connected

getClient

public org.apache.curator.framework.CuratorFramework getClient()

Provides access to the underlying CuratorFramework instance.

Returns:

the CuratorFramework instance

addListener

public boolean addListener(ZooKeeperConnectionListener listener)

Add a ZooKeeperConnectionListener.

Parameters:

listener - the listener to add

Returns:

true if the listener was added or false if it was already registered

removeListener

public boolean removeListener(ZooKeeperConnectionListener listener)

Remove a ZooKeeperConnectionListener.

Parameters:

listener - the listener to remove

Returns:

true if the listener was removed or false if it was never registered

isAutoStartup

public boolean isAutoStartup()

Specified by:

isAutoStartup in interface org.springframework.context.SmartLifecycle

setAutoStartup

public void setAutoStartup(boolean autoStartup)

Set the flag that indicates whether this connection should be started automatically.

Parameters:

autoStartup - if true, indicates this connection should be started automatically

setRetryPolicy

public void setRetryPolicy(org.apache.curator.RetryPolicy retryPolicy)

Set the Curator retry policy.

Parameters:

retryPolicy - Curator client RetryPolicy

getRetryPolicy

public org.apache.curator.RetryPolicy getRetryPolicy()

Return the Curator retry policy.

Returns:

the Curator retry policy

getPhase

public int getPhase()

Specified by:

getPhase in interface org.springframework.context.Phased

isRunning

public boolean isRunning()

Check whether this client is running.

Specified by:

isRunning in interface org.springframework.context.Lifecycle

start

public void start()

Starts the underlying CuratorFramework instance.

Specified by:

start in interface org.springframework.context.Lifecycle

stop

public void stop()

Closes the underlying CuratorFramework instance.

Specified by:

stop in interface org.springframework.context.Lifecycle

stop

public void stop(java.lang.Runnable callback)

Closes the underlying CuratorFramework instance and then invokes the callback.

Specified by:

stop in interface org.springframework.context.SmartLifecycle